Add error tracing support in Aspect implementation
Add error tracing support in Aspect implementation

This removes the parallelization feature from the Aspect codebase as
std::error::Error does not implement Send, so we cannot send the error
from a child thread to a parent thread.

This is clearly not an optimal implementation now, but we have hook
non-aborting-error tracing support, which is more important than
parallelization support, at least in this early stage of development.

An issue has to be opened for re-implementing parallelization of hooks.

matthiasbeyer/imag,matthiasbeyer/imag,mario-kr/imag,mario-kr/imag